Robin no start

[jwangelin]

Was doing some outdoor chores around the house with the PT425 today, the idle hasn’t been completely smooth. I turned it off for about 45 minutes and it wouldn’t run after that. It went from sounding like it was it was missing to firing only when the key was in start position to not catching even with starting fluid. Both plugs were fouled and it looked like there was some spark.

Any suggestions before I bug Terry tomorrow morning? I know this is not a great engine but I was hoping to keep it up and running a couple years before switching to a kohler or Honda.

Thanks for any suggestions,
Jon

 

[m5040]

I have a smaller model, so no first hand knowledge. But for suggestions, is the oil level the same or lower? Possibly higher??? The fuel tank is over the carb and if the needle and seat go bad, gas may leak by and flood the engine slowly at first and progressively get worse. The engine may also have a elect shut off valve for the gas when the key is off, but that will be open when the key is on, and again the carb needle/seat has to hold the gas back. Install new gapped plugs. See if that corrects it. Does it smoke black on start up? Long crank to dry out the plugs? You need to find out why your plugs are fouled, oil or gas. Air filter plugged? Good luck.

 

[jwangelin]

I have a smaller model, so no first hand knowledge. But for suggestions, is the oil level the same or lower? Possibly higher??? The fuel tank is over the carb and if the needle and seat go bad, gas may leak by and flood the engine slowly at first and progressively get worse. The engine may also have a elect shut off valve for the gas when the key is off, but that will be open when the key is on, and again the carb needle/seat has to hold the gas back. Install new gapped plugs. See if that corrects it. Does it smoke black on start up? Long crank to dry out the plugs? You need to find out why your plugs are fouled, oil or gas. Air filter plugged? Good luck.

The oil level didn’t seem to change, I’ll have to sniff the dipstick later to see if there was any contamination. No smoke on startup and I cleaned the plugs of the carbon buildup and no change.

 

[MossRoad]

Was doing some outdoor chores around the house with the PT425 today, the idle hasn’t been completely smooth. I turned it off for about 45 minutes and it wouldn’t run after that. It went from sounding like it was it was missing to firing only when the key was in start position to not catching even with starting fluid. Both plugs were fouled and it looked like there was some spark.

Any suggestions before I bug Terry tomorrow morning? I know this is not a great engine but I was hoping to keep it up and running a couple years before switching to a kohler or Honda.

Thanks for any suggestions,
Jon

Can you easily remove the valve covers and watch the rockers when you crank it? Both times I had non-starting issues, one of my rocker retainer nuts had backed off and a pushrod was no longer under the rocker. Once it even punched a hole in the valve cover. But mine's a Kohler.

 

[jwangelin]

Dang, I called Terry this morning and he hit it on the 1 try!

Now I have to wait or figure the proper procedure and specs to fixit up.

 

[MossRoad]

Dang, I called Terry this morning and he hit it on the 1 try!View attachment 4330671 Now I have to wait or figure the proper procedure and specs to fixit up.

See post 4 above

Where's Rodney Dangerfield when you need him?

 

[m5040]

Have you followed the required maintenance intervals for the engine? The only way I can see that happening is if you let the valve adjustment go way out of spec.

 

[MossRoad]

Have you followed the required maintenance intervals for the engine? The only way I can see that happening is if you let the valve adjustment go way out of spec.

It happened on my Kohler twice. There is no valve adjustment on the Kohler. You tighten the nut to spec and that's that. Hydraulic lifters take care of any lash.

I do not know about the Robin.

 

[jwangelin]

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Have you followed the required maintenance intervals for the engine? The only way I can see that happening is if you let the valve adjustment go way out of spec.

So far I am on hour # in owning the PT. Terry made it sound as though these robins will do this. I’ll have to build this into the maintenance schedule.

 

[m5040]

So far I am on hour #

in owning the PT. Terry made it sound as though these robins will do this. I’ll have to build this into the maintenance schedule.

I was unaware that some of these little engines had hyd lifters. If kohler had them, maybe yours does to. I would still look through your owners manual for the engine and see if any adj procedure for the valves. It doesn't seem right that it would be normal for the valve train to come apart like that.
Are you up on the oil change interval? I think it is only 50 hours. Maybe if an interruption in the oil pressure could make the lifters collapse?

 

[jwangelin]

The Robins are prone to having these pop out I understand. Terry was quick to suggest that that was the problem. The little sheet metal guide was bent a little, but I was able to get it back to where it should be. I still may order a new one.

 

[MossRoad]

The Robins are prone to having these pop out I understand. Terry was quick to suggest that that was the problem. The little sheet metal guide was bent a little, but I was able to get it back to where it should be. I still may order a new one.

Does that engine have a valve adjustment procedure?

 

[jwangelin]

Nothing seems to be simple.
Fortunately the procedure is the same for most OHV engines except it wasn’t as easy as others. I had to reset it multiple times before it was set. The tough part dead finding TDC, the shroud doesn’t move enough to remove it. I did drill a [emoji[emoji6][emoji[emoji6]]]” hole in the top of the shroud so as to move the flywheel with a screwdriver. Of course I also lost a locknut and the threads are not standard. A couple new ones are on order. I pulled the metal shroud below the spark plug and cleaned the mess on the bottom of the tub looking for the nut. Nothing. From all the poking around the (now) rigid fuel line began to weep so that got replaced. Next I found the exhaust on one side was loose and the nuts were all in so I added washers and its snug now. This got me to wonder if it would have been easier to pull the engine. Are there lovejoy connections inside the housing adapter? I wish the rear of the PT opened up. I’ll probably look to pulling the engine come springtime so as to throughly cleaning out the tub.

 

[MossRoad]

Pulling the engine is a last resort, in my opinion, due to the amount of hydraulic plumbing that has to be dealt with.

I pulled mine last year due to a phantom oil leak. (found it, repaired, OK). I bought a set of hydraulic caps and plugs before I even started based on advice from the group. I was a couple short and bought another set. Cleanliness is of utmost importance.

Yes, there are lovejoy connectors between the tram pump and engine. Mine has pumps on both sides of my engine. Can't remember quickly if there are lovejoys on the PTO pump side of mine.

All in all, it wasn't too difficult to pull the engine, and put it back again. I think I could pull it again in around and hour now that I have done it once before.

 

[MossRoad]

Ahh, here's a picture thread I did of my engine removal. Mine has lovejoys on both ends. Took me an hour and a half at the time. Read if you're interested...

2001 PT425 Kohler CH25 Oil Leak - Pull The Engine

My 2001 PT425 developed an oil leak. About 1/2 a quart every 20 minutes. Can't seem to locate it, other than a pool of oil under the engine. So time to pull the engine, put it on a stand, clean it up, and run it to locate the leak. Trying to avoid disconnecting hydraulic hoses. Pulled the gas...

www.tractorbynet.com

 

[jwangelin]

Finally got my PT up and running. Unfortunately while getting the valves adjusted one of the lock nuts fell off in the dark and disappeared in the grass or the oil and grass mixture in the tub. I had to wait over a week for one to get shipped in. Since I couldn’t take the fan shroud off I drilled a ” home and moved the flywheel alone with a screwdriver to find TDC. My Ace Hardware had a plug that filled the hole.

 

[MossRoad]

Two suggestions...

https://www.harborfreight.com/9-function-metal-detector-67378.html

https://www.harborfreight.com/18-inch-telescoping-magnet-37187.html

 

[jwangelin]

Two suggestions...

I know, I thought about it. I figure next time I’ll schedule a breakdown for the PT inside the garage.

 

[MossRoad]

That's the best place!